{1: 1}
{1: 1, 3: 1, 8: 1}
{1: 1, 3: 1, 8: 2, 7: 2, 11: 1}
10 11
{1: 1, 3: 2, 8: 3, 7: 3, 11: 1, 10: 3}
{1: 2, 3: 3, 8: 4, 7: 4, 11: 1, 10: 4}
4